Focus on a review of aphasia - Essay Example

Introduction A specific language impairment (SLI) such as aphasia (speech), alexia (reading), or agraphia (writing) may be induced, genetic or developmental in form. SLIs occur because of neurological, sensori-motor, non-verbal cognitive or socio-emotional dysfunctions (Harley, 2001; Hunt & Ellis, 2004). There has been active research into aphasia, alexia and agraphia for the past four decades. Language acquisition or its impairment is of primary concern in industrialized nations given the emphasis placed on text in day to day living, in education, at the supermarket, at work and on roads, and for leisure purposes for example. This paper will focus on a review of aphasia, which can be more explicitly defined as the loss or impairment of the ability to use or comprehend words due to brain damage (Banich, 2004; Carroll, 2004). Some of those who experience aphasia are predominantly affected in the expressive language (what is said) whilst others are predominantly affected in their receptive language (what is understood), other people who experience aphasia have both expressive and receptive language dysfunction. In general, language disability occurs in the form of talking and understanding and also in reading and writing. The extent of the dysfunction and the nature of the problems a person will experience are dependant on numerous psychosocial and environmental factors, as well as the amount and location of damage in the brain. Obviously this presents numerous communication difficulties for those who experience aphasia, and subsequently affects their ability to fully contribute and integrate with the wider community. Firstly, a review of aphasia aetiology will be given. Secondly, the incidence of the language impairment will be presented. Finally, patterns of the deficit will be highlighted, followed by aphasias theoretical significance and prognosis with respect to intervention. Aetiology Aphasia is a specific language impairment that results from brain damage at the language centers (Brocas or Wernicks areas for example) (Harley, 2001). For most right-handers and about half the population of left-handers, when damage occurs to the left side of the brain aphasia can occur. Consequently, a person who was previously able to communicate by way of speaking, listening, reading and writing becomes severely limited in these activities as their ability to communicate has diminished. A stroke is the most common reported cause of aphasia, but gunshot wounds, blows to the head and other brain trauma or tumor can also cause aphasia. Aphasia tends to be first recognized by a general practioner or physician who is treating a person for brain injury, such as a neurologist (Pinker, 1994). When a person is not able to follow commands, answer questions, to name objects or to converse in a logical and understandable way, the physician may suspect aphasia. The person would then be referred to a speech-language pathologist who would undertake a comprehensive examination of their ability to speak, read, write and understand language. These tests would include (Carroll, 2004): Fluency, vocal quality and loudness, and the pronunciation and clarity of speech Strength and coordination of the speech muscles Understanding and use of vocabulary (semantics) and understanding and use of grammar (syntax) are evaluated. Understanding and answering both yes-no (e.g., Is your name Bob?) and Wh- questions (e.g., What do you do with a hammer?). Understanding extended speech. The person listens to a short story or factual passage and answers fact-based (the answers are in the passage) and inferential (the patient must arrive at a conclusion based on information gathered from the reading) questions about the material. Ability to follow directions that increase in both length and complexity. Ability to tell an extended story (language sample) both verbally and in written form. Can the person tell the steps needed to complete a task or can he or she tell a story, centering on a topic and chaining a sequence of events together? Can he or she describe the "plot" in an action picture? Is his or her narrative coherent or is it difficult to follow? Can the person recall the words he or she needs to express ideas? Is the person expressing himself or herself in complete sentences, telegraphic sentences or phrases, or single words? Is speech slurred and difficult to understand or is it intelligible? Social communication skills ( pragmatic language) Ability to interpret or explain jokes, sarcastic comments, absurdities in stories or pictures (e.g., What is strange about a person using an umbrella on a sunny day?). Proficiency with initiating conversation and conversational topics, taking turns during a discussion, and expressing thoughts clearly using a variety of words and grammatical constructions. Ability to clarify communication when his or her conversational partner does not understand. Reading and writing of letters, words, phrases, sentences, and paragraphs. The speech-language pathologist may look at the quality of the language expression, accuracy of spelling, and letter formation and spacing of words and letters on the page (to identify or rule out possible movement and/or visual-perceptual difficulties). Incidence The population estimate for cases of aphasia in the UK is around a quarter of a million (Carolei, Sacco, De Santis, & Marini, 2002). The majority of aphasia cases are due to stroke. Stroke is one of the leading causes of death and it is a major cause of long-term disability in adults, including specific language impairment. It is estimated that stroke incidence ranges from 500, 000 - 760, 000, these figures being based on symptomatic strokes, and so do not reflect the cases due to tissue death due to limited blood supply and hemorrhages. Literature attests to approximately 80, 000 people acquiring aphasia each year, and the number of people affected appears to be increasing rapidly each year with the effect of aging and people living longer. Although anyone can acquire aphasia most cases do not occur until the middle to late stages of adulthood, with women and men being affected equally, a well as the impairment occurring across cultures. Pattern of Deficit Motor or Brocas aphasia is also called "expressive", "anterior", or "nonfluent" aphasia. For most people the Brocas area is in the lower part of their left frontal lobe (Carroll, 2004). This area is one of the main language centres in the brain, and controls the motor aspects of speech. Usually word meanings can be understood but the person has issue performing the motor or output aspects of speech. Depending on severity, symptoms range from mild (cortical dysarthia) with intact comprehension and the ability to communicate by way of writing, to a complete loss of speaking out loud. Speaking tends to be in short, meaningful phrases that take effort. They may leave out small words such as "is", "and" and "the". They tend to be aware of their language issues and can become frustrated. Sensory or Wenickes aphasia is also called "receptive", "posterior" or "fluent" aphasia (Hunt & Ellis, 2004). The damage is to the temporal lobe and people may speak in long sentences that have no apparent meaning, add unnecessary words and may even create their own novel words. There is often a lot of difficulty understanding speech and the person tends to be unaware of their mistakes in language and communication. Overall, there is a loss of comprehension of spoken language, loss of the ability to read silently and to write, and a distortion of articulate speech. They may still speak with a natural rhythm though, and word memory tends to remain with words most often chosen correctly. There also tends to be associated alexia, agraphia, acalculia, and paraphasia frequently. Also, some people may be euphoric and/or paranoid due to cortical lesions in the posterior of the first left temporal convolution. A third pattern of deficit is total or globalaphasia which is the loss of nearly all speech and language functions when extensive portions of the language areas are affected (Carroll, 2004). This presents as dramatic communication dysfunction and they may be very limited in their ability to speak and comprehend language. The symptoms are severe Brocas and Wenickes aphasia combined. However, other cognitive functions remain unaffected. People tend to by mute, or to use repetitive vocalization, they may frequently use simple words such as expletives. Theoretical Significance Aphasia as a phenomenon confirms the argument that language centres in the brain are separate domains. The different patterns of deficit highlight the distinct properties of language, such as syntactic comprehension having properties that differentiate it from other aspects of language (Kaan & Swaab, 2002). This may indicate a specific locus of syntax in the cortex; nueruoimaging could help support or disconfirm this argument. Alternatively, research on propositional reasoning which involves theory of mind, appears to show that adult reasoning can occur in the absence of explicit grammatical knowledge, however, that the presence of such knowledge does not account solely for the ability to reason (Siegal, Varley & Want, 2001). This information may further understanding of how reasoning is linked to language by way of conversational awareness and experience in communication Additionally, research into aphasia can reveal the neural organization of language and the factors it is dependant upon to produce language, and to perceive it correctly (Hickok1, Ursula Bellugi & Klim, 1998). The impairment also brings to light language questions, such as: Is the left-hemisphere dominance for language a function of specialisation or of domain-general specialisations, for example temporal processing or motor planning. Mapping of neurological similarities and differences between the different language abilities of people may indicate modality-specific contributions to brain organization with regard to language. Prognosis with Respect to Intervention In general, experiences of aphasias can be aided through specific rehabilitation techniques (Miller, & Spilker, 2003). The speech-language pathologist works in cooperation with a team of rehabilitation and medical professionals and families and teachers or employers to determine a comprehensive treatment plan for the person experiencing aphasia. This may include exercises to improve specific language skills. This may be naming of objects, following directions and answering questions. The challenges vary according to the degree of impairment and individual needs, and tasks become more complex as their skills improve. Overall, the level to which a person can recover their language abilities is dependant of on the amount of brain damage and its location (Miller, & Spilker, 2003). Also a persons age, general health and their motivation and willingness to participate in their treatment also contributes. Whether they are left or right-handed will also be a factor, as the language areas of the cortex tend to be in both the left and right hemispheres of left-handed people. They may then recover faster and more fully. Timing of treatment and its intensity will also contribute to the eventual outcome. However, outcomes are difficult to predict given the variability of impairment across individuals. Those who are younger or who have less extensive brain damage tend to recover better and more rapidly. Generally, skills in language comprehension are recovered more fully and quicker than those skills involving expression. References Banich, M.T. (2004) Cognitive Neuroscience and Neuropsychology, (2nd ed). New York: Houghton-Mifflin Carolei, A., Sacco, S., De Santis, F., & Marini, C. (2002) Epidemiology of stroke. Clinical and Experimental Hypertension, 24(7-8): 479-483. Carroll, D.W. (2004). Psychology of Language (4th ed.). London: McGraw Hill. Harley, T. (2001) The psychology of Language (2nd ed.) Sage Bush: Psychology Press. Hickok, G., Bellugib, U., & Klim, E. (1998) The neural organization of language: Evidence from sign language aphasia. Trends in Cognitive Sciences, 2(4): 129-136 Hunt, R. Reed & Ellis, E. (2004) Fundamentals of Cognitive Psychology. London: McGraw Hill. Kaan, E. & Swaab, T. Y. (2002) The brain circuitry of syntactic comprehension. Trends in Cognitive Sciences, 6(8): 350-356. Miller, E.T., & Spilker, J. (2003) Readiness to change and brief educational interventions: Successful strategies to reduce stroke risk. Journal of Neuroscience Nursing, 35(4): 215- 222. Pinker, S. (1994) The Language Instinct. New York: William Morrow & Company. Siegal, M., Varley, R., & Want, S. (2001) Mind over grammar: reasoning in aphasia and development. Trends in Cognitive Sciences, 5(7): 296-301. Read More